This invention relates to the packaging of compressible, generally fibrous material, and most particularly to packaging rolled mineral fiber e.g. fiberglass insulation. It will be understood hereinafter, that where reference is made to "fiberglass insulation rolls or the like", such reference is made to be representative, not limiting, in that other materials having packaging related characteristics similar to those of fiberglass insulation rolls may likewise be processed according to the method and apparatus of the present invention. For example, bags of insulation (preferably in bags of coarse mesh for air passage during compression) may be used, the shapes of which could be pillow-like or otherwise shaped and for purposes of this invention are considered to be sufficiently cylindrical and roll-like to be processed by this invention. Also, while this invention is preferably used to compress the roll-like shapes being packaged, compression is not an essential activity, in that, depending upon the size of the shape being packaged, it could conceivably be packaged by means of this invention without being compressed.
Various techniques have heretofore been employed to package fiberglass and like material. For example, the application of a package wrapper to fiberglass rolled material is disclosed in U.S. Pat. No. 3,717,973. Another fiberglass packaging apparatus is disclosed in U.S. Pat. No. 3,964,232. Still another method and apparatus is disclosed in U.S. Pat. No. 3,458,966.
In packaging rolled fiberglass insulation, it is becoming increasingly important that the insulation, if compressed, have a high degree of thickness recovery, because if such recovery is poor, considerable excess thickness is required prior to packaging in order for the product to have nominal thickness after unpacking. Also, in certain types of packaging, such as where a fiberglass roll is placed in a generally gas-impervious sleeve, which then has a vacuum drawn on it to pull the sleeve tightly around the package, it has been known that the size of the fiberglass roll may be reduced, but such has often resulted in undesirable substantial fiber breakage, and highly uneven compression, which in turn renders the resultant product often at least highly unsightly, if not unuseable.
Other types of packaging of fiberglass insulation mats are known, such as an alternating layer package (or zigzag packaging), but such packages can also yield undesirable fiber breakage at the location of the folds.
Nevertheless, it is highly desirable to, in some manner, reduce the size of fiberglass packages, to reduce the handling costs, to reduce the freight costs of transporting large bulky packages, and to obtain greater efficiency of storage.